Railway-traffic-controlling apparatus



June 1 1926.

1,587,163 R. A. MCCANN I RAILWAY TRAFFIC CONTROLLING APPARATUS Filed May 10 1923 INVENTOFL;

aw/2M M ATTORNEY Patented June 1, 1926.

v uurrsn sra'res rarsnr orrics.

RONALD A. MCCANN, OF SWVISSVALE, PENNSYLVANIA, ASSIGNOR- T THE UNION SWITCH. & SIGNAL CQMPAITY, OF SRVIfiSVALE, PENNSYLVANIA, A COREORATION OF PENNSYLVANIA.

RAILWAY--TRAFFIC--CONTROLLING APPARATUS.

Application filed May 10,

My invention relates to railway traffic controlling apparatus, and particularly to apparatus of the type wherein alternating current or currents are supplied to the trackway for the control of train carried governing mechanism.

In one arrangement of apparatus of the type mentioned, it has been suggested to cmploy the usual track circuit current, that is, the current which energizes the track relays, as one of the currents for controlling the train carried governing mechanism, such control being effected by this current through the medium of receii' ing appliances at the front end of the train. When this is done, it is obvious that the source of track circuit current must always be connected across the rails ahead of a train.

In the case of a double track railroadin which traffic on each track normally moves in one direction, only, this requirement is readily met in so far as movements in the normal direction are concerned because the source of track circuit current for each section is then connected across the rails adjacent the exit end of each section in accordance with standard practice in automatic block signaling. In the case of single track roads, however, it is necessary for trains to proceed over the track in both directions, and in such instances with only the trackway apparatus thus far mentioned, trains moving in one direction would not receive track circuit current. One feature of my invention is the provision of means, located in the trackway, for connectinga'source of track circuit currentacross the rails at either end of the section, thus permitting train movements in both directions.

I will describe one form of railway traflic controlling apparatus embodying my invention, and will then point out the novel fea tures thereof in claims.

The accompanying drawing is a diagrammatic view showing one form and arrange ment of railway traffic controlling apparatus embodying my invention.

Referringto the drawing, the reference characters 2 and 2 designate the track rails 59 of a railway over which traflic'moves in both directions. These rails are divided by means of insulated joints 1 into a plurality of insulated track sections A-B, BC, etc. Each track section is provided with, a track trans- 1923. Serial No. 637,929.

location and having a secondary winding 5 connected across the rails adjacent the left hand end of the section. Interposed between one terminal of this secondary winding 5. and the track rails 2 is an impedance 7, one function of which is to limit theoutput of the transformer when its terminals are shortcircuited by the wheels and axles of a train occupying the associated section. A similar track transformer designated by the reference character U with an exponent corresponding to the location is provided for each section and has its secondary winding 83 connected across the rails adjacent the right hand end of the section. An impedance 85 is connected between this impedance and one rail 2 of the associated section. Each section is'provided with two track relays designated by the reference characters R and D with'exponents corresponding to the locations, which relays are located at the left hand. and right hand ends of the section re spectively. Associated with each relay R is a directional relay K, a line relay H, and a stick relay S. A repeater relay, designated by the reference character P with an exponent corresponding to the location is associated with each relay D.

Referring particularly to section A-B, the relay E is connected, by means of wires 9 and 10, across the rails at the left hand end of the section, and so it is also connected across the secondary winding 5 of transformer T. In order to protect the relay, an impedance 8 is connected in series therewith, which impedance may be shortcircuited when transformer T is not energized. The directional relay K is provided with a circuit which passes from the right hand terminal of the secondary winding 56 of a line transformer F through wires and 541, back contact 52-51 of relay S wire 15, relay K and Wires 13, 14, 17, 19 and 60 back to the left hand terminal, of

* secondary winding 56 of transformer F of secondary winding 56 of transformer F through wires 58. 23 and 21, front contact 2829 of track relay R wire 87, directional relay K, wire 13 and back to the left hand terminal of secondary winding 56 as before. This circuit is closed only when relay R is energized. It is clear, therefore, that re lay K is energized when relay R is energized, or relay S is (ole-energized. Line relay H is provided with a circuit which passes from the right hand terminal of the secondary winding 56 of the line transformer F for the section next in advance, through wires 55, 58 and 59, front contact 36-37 of relay H wire 39, back contact l8%9 of relay S wire 64, front contact 7071 of relay D wire 27, front contact -26 of relay R wire 16. line relay H and wires 18, 19, 60 and 86 back to the left hand terminal of secondary winding 56 of transformer F An auxiliary circuitis provided for relay H which passes from the right hand terminal of secondary winding 56 of transformer F through wires and 53, front contact 47-48 of relay S wire 641;, front contact 70-71 of relay D wire 27, front contact 25 26 of relay R wire 16, winding of relay H and wires 18, 19, and 86 back to the left hand terminal of secondary winding 56 of transformer F It is clear, therefore, that relay H is energized when relays R D and H are energized and relay S is (lo-energized; or when relays R D and S are energized. Stick relay S is provided with a pickup circuit which passes from the right hand terminal of secondary winding 56 of transformer F through wires 63 and 67, back contact 7374t of. relay 1), wire 69, front contact 3 l-85 of re ay vl-l", wires 41 and 43, relay S, and wires 42 and 60, back to the lefthand terminal of secondary winding 56 of transformer F". This relay is also provided with a stick circuit which passes from the righthand terminal of secondary winding 56 of tiaiis'foi'ii'ieizF through wires 58 and 59, back contact 3638 of relay H wire ll), front contact l5&6 of relay S wire ll, relay S and wires 42 and 60 back to the left hand terminal of winding 56 of transformer F. It follows that when relay D is tie-energized and relay H is energized, the relay S will. he picked up, and that it will thereafter stick up through its own front contact while relay H is de-energized. The impedance 8 is provided with a shunt which comprises wires 11 and 12 and back contact 32 33 of relay R whereby this impedance is short-circuited when relay R is tie-energized. The primary winding 6 of track transformer T is supplied with alternating current through a circuit passing from the right hand terminal of secondary winding 56 of transformer l through wires 58, 23 and 22, front contact ESQ-Q31 of relay K wire 62, winding 6, and

wires 14-, 1.7, 19 and 60 back to the left hand terminal of secondary winding 56 of transformer F. This circuit is closed only when relay R is energized in which case section AB is supplied with track circuit current from its left hand end. by means of transformer T The energizing circuit for relay D passes from rail 2 through wire 82, relay D wire 76, back contact 78-79 of relay P and wire 68 back to the rail 2. Evidently this circuit is closed only when relay P is (lo-energized. Relay P is provided with a circuit which passes from the right hand terminal of secondary winding 56 of transformer F through wires 55 and 54, front contact 52-50 of relay 8, wire 24:, back contact 2590 of relay R wire 27, back contact '70--72 of relay D wire 75, relay P and wires 88, 61, 17, 19 and 86, back to the left hand terminal of secondary winding 56 of transformer F". This circuit is closed only when relays R and D are both de-energized and relay 8" energized. A circuit is provided also which passes from the right hand terminal of seeondary winding 56 of transformer F, through wires 63 and 66, front contact 778() of relay R wire 81, primary wind ing Set of transformer U and wires 61, 17, and 19, back to the left hand terminal of secondary winding 56 of transformer F. This circuit is closed only when relay P is energized in which case the rails of section AB are supplied with track circuit current from transformer U The operation of the entire system is as follows: Normally, that is, in the absence of trains, each relay K is closed and each relay P is open so that track circuit current is supplied to each section at the left hand end, and track relays R and D are both in the track circuits and are both energized. I will now assume a train to be moving from left to right. As this train enters the section to the left of point A, track relay D will be deenergized thus closing the circuit for stick relay S through contact 737-il. Since the relay H is energized and contact 3 l35 thereon is closed, stick relay S will be picked up. As the train enters section AB both track relays R and D will he deenergized. The opening of the front contact of these relays de-energizes line relay H which opens its front contacts and interrupts the pick-up circuit for stick relay S This relay does not open however because it is now energized over its own front contact and a back contact on the line relay H The closing of back contacts 259() and -72 on relays R and D respectively completes the circuit for relay P which circuit passes over front contact 52--50 of stick relay S Relay P therefore closes and by so doing disconnects track relay D from the track circuit by opening its back contact 7879 and at the same time connects a source of energy to the primary 84E of track transformer U by closing its front contact. But relay K is tie-energized since one of its circuits. was opened by the opening of back contact 5251 of stick relay S and the other of its circuits was opened by the de-energization of track rclay R and the consequent opening of front contact 28*29 thereon. The de-energizati on of relay K disconnects energy from the primary winding of transformer T by the opening of front contact 3031 and closes the shunt around impedance 8 by closing back contact 8233. Under these conditions, then, energy is supplied to the track circuit from transformer U which is located in advance of the train. As the train clears the point A, track relay D closes but the opening of its back contact does not deencrgize the stick relay S which held closed by energy over the circuit through its front contact and back contact 8638 of relay H As the train passes out of the section AB at point B, energy flows from transformer U through the rails and energizes relay R The opening of its back contact 2590 de-energizes relay P which opens, re-connecting relay D to the track circuit and disconnecting energy from transformer U In the meantime however the closing of front contact 28--29 has energized relay K The shunt around impedance 8 is therefore opened and energy is reconnected to the transformer T The operation of the apparatus in section B-G is exactly similar to that just described for section AB and therefore stick relay S will now be energized and as a result, line relay H will now be energized over front contact 48-457 of stick relay S and front contacts of relays R and D Stick relay S is therefore de-energized thus restoring the apparatus associated with section A-B to normal. When the train has proceeded out of section BO, relay S is die-energized and the control. of line relay H now passes over back contact l8--49 of stick relay S and front contact 8637 of relay H thus restoring the section AB to its normal condition. One feature of my invention is the provision of means for delaying the opening of the stick relay till after the control of relay H is completed.

I will now assume a train to be moving from right to left and to enter section EC. Both track relays R and D will be de energized, thus opening the circuit for line relay H at their front contacts. But the opening of relay H does not affect any of the other relays so the transformer U will remain disconnected from the track and the transformer T will continue to feed the rails of the section. As the train passes into section AB relays R and D will both be (ls-energized. Now when the rear of the train clears point B, energy from transformer T picks up both relays R and D and completes the circuit for relay H But since relay D is (ls-energized, the closing of contact 34-35 on line relay 'H completes the pick-upcircuit for stick relay S which closes but thisis of no consequence as all of the circuits which this relay controls-are open at other points. As the train clears point A relay D is energized thus de-enen gizing stick relay S and restoring section BC to normal condition. It is clear,there fore, that for traflic moving from right to left the track circuit current is always supplied from ahead of the train.

' Although I have herein shown and de scribed only one form of railway traffic controlling apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope ofthe appended claims with out departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. Railway traffic controlling apparatus comprising a section of railway track, a source of track circuit current normally connected across the rails adjacent the left hand end of said section, a track relay connected across the left hand end of said section, a second source of track circuit current located at the right hand end of said section but normally disconnected therefrom, a second track relay normally connected across the rails adjacent the right hand end of said section, a normally de-energized stick relay arranged to be energized by a train approaching said section from the left and to remain energized while such train is passing through the section, a directional relay controlled in part by said first track relay, and in part by said stick relay for disconnecting said first source from the rails of said section, and a repeater relay controlled by said track relays and by said stick relay for connecting said second source with and disconnecting said second track relay from the rails of the section.

2. In combination, asect-ion of railway track, a first source of current normally con nected with the rails adjacent one end of said section, a second source of current adj acent the other end of the section but normally disconnected from the rails, a normall de-energized relay, means controlled by a train approaching said section from one direction but not from the other direction for energizing said relay before the train enters the section, a track relay for said section, means controlled by said track relay for keeping said normally de-energized relay energized while a train which has caused it to become energized is passing through the section, a directional relay controlled by said normally de-energized relay and by said track relay for disconnecting said first source from the track rails when a train passes through the section in the first mentioned direction, and means controlled by said normally de-energized relay and by said track relay for connecting said second source with the rails of the section.

3. Railway traffic controlling apparatus comprising; a section of railway track, a source of track circuit current normally connected across the rails adjacent the left hand end of said section, a track relay connected across the left hand end of said section, a second source of track circuit current located at the right hand end of said section but normally disconnected therefrom, a second track relay normally connected across the rails adjacent the right hand end of said section, a line relay controlled in part by said track relays, a stick relay controlled in part by said line relay, a repeater relay controlled by said stick relay and said track relays, a directional relay having an energizing circuit including a source of energy and a front contact on said first track relay and a second energizing;- circuit including a source of energy and a back contact on said stick relay, means controlled by said direc tional relay for disconnecting said first source, and means controlled by said repeater relay for connecting said second source and disconnecting said second track relay.

4. In combination, a forward and a rear section of railway track. a track relay connected across the rails at the left hand end of said rear section, a second track relay connected across the rails at the right hand end of said rear section, a line relay for said forward sect-ion, a stick relay for said for ward section controlled in part by said line relay, and a line relay for said rear section controlled by said track relays, said first line relay and said stick relay.

In testimony whereof I aflix my signature.

RONALD A. MCCANN. 

